Current-induced spin polarization in spin-orbit-coupled two-dimensional electron systems

TL;DR

This paper rederives and analyzes current-induced spin polarization in spin-orbit-coupled 2D electron systems, proposing a simple understanding and demonstrating its validity with formalism, highlighting stronger effects in metals and semimetals.

Contribution

It introduces a new statistical picture for understanding CISP and applies nonequilibrium formalism to validate it in Rashba-Dresselhaus systems, with practical implications.

Findings

CISP increases with spin splitting strength.

Stronger CISP observed in metals and semimetals.

Proposed application for in-plane spin-Hall pattern.

Abstract

Current-induced spin polarization (CISP) is rederived in ballistic spin-orbit-coupled electron systems, based on equilibrium statistical mechanics. A simple and useful picture is correspondingly proposed to help understand the CISP and predict the polarization direction. Nonequilibrium Landauer-Keldysh formalism is applied to demonstrate the validity of the statistical picture, taking the linear Rashba-Dresselhaus [001] two-dimensional system as a specific example. Spin densities induced by the CISP in semiconductor heterostructures and in metallic surface states are compared, showing that the CISP increases with the spin splitting strength and hence suggesting that the CISP should be more observable on metal and semimetal surfaces due to the discovered strong Rashba splitting. An application of the CISP designed to generate a spin-Hall pattern in the inplane, instead of the out-of-plane, component is also proposed.